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1986 Alum head L98 - Which sensor is in the head below exhaust manifold on passenger side? It's not the one with the mushroom-type connector (Driver's side). It's the one with the tab-type connector.
For 1986, the sensor in the passenger side cylinder head, between cylinders #6 and #8, is the temp sensor for the dash temp read out. The coolant temp sensor for the ECM is located in the front of the intake manifold, pointing straight forward.
Keep in mind that the Coolant Temp Sensor sends a signal to the ECM which controls the main cooling fan by way of the relay coil. The ECM turns on the main fan. If you have the heavy duty cooling package, the switch turns on the the secondary fan and does not go through the ECM.
If you need more information let me know.
Last edited by 87vetter; Feb 1, 2005 at 07:10 PM.
Reason: Bad spelling
Some manuals have it reversed though, so don't get tripped up.
Jake
Part of the problem with sensor/switch locations, is that the General chose to swap locations for the aux fan switch with the dash readout sending unit, several times. As you well know you are correct for the '86. Whenever the question comes up, I have to look it up in my parts book, to be sure I have the correct answer for the subject year.
Originally Posted by 87vetter
Keep in mind that the Coolant Temp Sensor sends a signal to the ECM which controls the main cooling fan by way of the relay coil. The ECM turns on the main fan. If you have the heavy duty cooling package, the switch turns on the the secondary fan and does not go through the ECM.
If you need more information let me know.
That is all fine and good, as long as you know what device is mounted where, and it's function. FYI, in '84 there is NO ECM involvement in the fan operation.